This invention relates to apparatus for use in the production of wiring harnesses or cable forms and in particular to improved loom tables and more particularly to a loom table having a construction to facilitate the releasable attachment of guide pins. The invention also relates to the production of a multiplicity of similar wiring harnesses in a production run comprising a multiplicity of cycles in each of which a wiring harness is produced and to that end the invention concerns the use of the improved forms of loom table as specified above.
As is well known to those skilled in the art a wiring harness is an assembly of wires bound or otherwise held together as a bundle for providing the required electrical connection between various electrical components in a piece of equipment. Such harnesses are extensively used in the manufacture of domestic and industrial powered vehicles, such as automobiles, lorries and industrial trucks which include a large number of such electrical components. When the wiring harness is disposed in the vehicle, it is commonly disposed in a channel or channels or is otherwise fixed to the frame of the vehicle, the various wires of the harness being individually identified by colour coding and extending between switches, power sources, lighting equipment, engine or motor components, fuses, steering gear or other components of the vehicle.
It will be appreciated that the different components and relative disposition thereof in different vehicles requires that harnesses be specially designed for the particular vehicle concerned. It has been common practice in the past to lay wire lengths along predetermined paths marked on a board and defined by a multiplicity of pins held in and projecting from the board, serving to hold wires in place until all of the wires are laid. It has been common practice to provide a different loom board for each different type of wiring harness which is to be produced but such a practice requires the production of a large stock of loom boards and is thereby rather inconvenient. Although, as noted below, it has been proposed to provide a loom board or table which can accommodate releasable pins, prior loom tables have not been particularly well adapted for the insertion and removal of guide pins, as for example by means of an automatic manipulator, so that the wiring paths defined by a particular pattern of pins can readily be changed for the production of a different harness.
One object of the present invention is therefore to provide a loom table which is well adapted for the easy insertion and removal of guide pins, particularly by means of an automatic manipulator used for that purpose.
In the laying of wires to form a wiring harness it has been common practice to use equipment commonly known as an X-Y plotter which for any selected wire draws the wire from a spool or other supply along the path defined, for example, by guide pins. In practice it has been necessary to employ special devices for terminating the ends of wires so as to secure them in position on the loom table while the remaining wires of the harness are laid. Such expedients are generally inconvenient either because they require additional equipment for attaching terminal fittings or other anchorages to the wires or because they require the disposition of special wire holders on the wiring table itself.
It is therefore another object of the present invention to provide a loom table by means of which ends of wires can be conveniently anchored in any desired position without requiring the use of tools other than those for laying or cutting the wire and without requiring the fitment of wire holders (other than the aforementioned guide pins) to the table.
A further object of the present invention is to provide an improved method of producing wiring harnesses which is well adapted for automatic performance and which can be performed by an automatic manipulator in conjunction with a loom table as set forth herein.
A further object of the invention is to provide apparatus for use in the production of wiring looms particularly adapted for use in conjunction with shouldered guide pins and in which apparatus the loom table itself is adapted for holding the ends of wires laid on the table without requiring any special clips or fitments for the ends of the wires.